Sound transmission and broadcasting underwater has been used in scientific experiments, industrial applications and in the aquatic sports and entertainment field for the transmission of voice instructions to athletes or artists performing underwater. The most common type of underwater sound delivery systems uses piezoelectric transducers, examples of which are disclosed in U.S. Pat. Nos. 3,100,291 and 3,718,897 to Abbott and 3,391,385 to Lubbell. This type of transducer tends to be heavy, has a very poor response to frequencies below 300 Hz, and is usually very expensive.
There is a need for a high-fidelity sound system capable of operating underwater as well as above.